Heat Transfer Calculation And Program Development Of Space Radiation Heat Dissipation Carbon Foams

The thermal discharge system is one of the important components of the whole nuclear-powered aircraft.Its main function is to discharge the redundant waste heat that cannot be used in the whole system to the space,so as to effectively ensure the thermodynamic efficiency of the aircraft and the thermal balance of each system.The space high-power thermal discharge system is mainly composed of heat pipe,foam carbon heat exchanger,heat exchange circuit and radiation heat dissipation plate.Among them,the heat pipe,heat exchange circuit and radiation cooling plate can be calculated in cartesian coordinate system because of their regular structure and simple material structure.Foam carbon heat exchanger is an important heat exchange device in the whole heat transfer system,so the study of its heat transfer characteristics plays a crucial role in the optimization of the parameters of the whole heat emission system.In this paper,based on the reconstruction of carbon foam porous materials,the effects of porosity and growth probability in different directions on porous structures were studied by using the random parameter method to reconstruct two-dimensional and three-dimensional porous media.The relationship between porosity and equivalent thermal conductivity was calculated by the lattice boltzmann method.In order to solve the numerical calculation of irregular graph,the method of analyzing DXF file to obtain the irregular boundary value and establishing the conformal coordinate system was used to divide the graph into grids.The method of transformation of differential equations was used to calculate the heat conduction in the body coordinate system,and the results were compared with those of fluent.